Pyrite is an opaque, metallic stone, often called "fool's gold" because of it's similar look to gold. Spot Pyrite is a form is pyrite ore exhibiting visible chunks of pyrite scattered amongst the matrix. The name pyrite derives from the Greek "pyros" for "fire" because sparks flew from it when hit with another mineral or a metal. Centuries ago, pyrite was polished by Native Americans and used as mirrors.